I have a customer who has two physical buildings (HQ and satellite office)
HQ have a dedicated BT leased line at 100mbps. They have a WatchGuard firewall, and the external interface is configured with a static public IP.
The Satellite office HAD a BT ADSL line with static IP. This was connected to a DrayTek 2830n router. This router has Wi-Fi VLANs enabled for staff and customers,
I also HAD 2 branch office (LAN-to-LAN, Site-to-site - whatever you want to call them) VPNs working (for staff networking and for VoIP phones).
However, the customer has "upgraded" the Satellite office line to BT Infinity. A Home Hub 5 was supplied by BT and now sits in the middle of what was working before. The DrayTek 2830n is now plugged in to the BT Home Hub 5, and of course the VPNs no longer work.
In the Home Hub, I have tried using Port forwarding of ports 50, 51, 500 and 1723 to the DrayTek, and I have tried adding the DrayTek as a DMZ, but I just can't get the VPNs to work.
Is there a way of doing this without ditching the current Home Hub and DrayTek 2830 in favour of a DrayTek 2860 VDSL router?